1 . Field of the Invention
The present invention relates to a module card retainer device for use in a personal computer, and particularly to a retainer device which can easily and effectively fix a module card or the like onto a printed circuit board.
2 . The Prior Art
Modularized PC boards and CPU cards have become a trend in the PC industry. Traditionally, a CPU is connected to a mother board either via a connector or direct soldering. However, an advanced manufacturing technique has replaced this method by firstly soldering the CPU onto a printed circuit board and then inserting the printed circuit board into a connector mounted on the mother board. Alternatively, the CPU is firstly combined with the PC board as a modularized unit and is then inserted into a connector mounted on the mother board. However, either the PC board or the modularized card is elevated above the connector, therefore, the PC board or the modularized card is apt to vibrate and adversely affect signal transmission. Normally, a retainer device is configured beside the connector in order to further fix the PC board or the modularized card. The related U.S. Pat. Nos. are 5,259,793, 5,429,523 and 3,829,741.
A conventional retainer device 1 shown in FIG. 1 is formed by integrated injection molding and comprises a base closure 11 from two distal ends of which two clamping arms 12 extend. Two seats 13 are respectively formed adjacent to two lower sides of each clamping arm 12. Each clamping arm 12 defines an inner channel 121 confronting each other and cooperating to receive a module card (not shown) therebetween. The base closure 11 defines a slot 111 for retaining a connector (not shown) into which a module card (not shown) or the like is inserted. Each seat 13 defines a cavity 131 for receiving a corresponding locking member 14. Each seat 13 defines an opening 1311 at a top thereof and a hole 1312 in a base thereof. Each locking member 14 has a base 142 and a vertical portion 141 extending upward from the base 142. A threaded hole (not shown) is defined from the base 142 through the vertical portion 141 for matingly engaging with a bolt (not shown). The base 142 is sized to be larger than the hole 1312 yet smaller than the opening 1311 defined in the seat 13. Each pair of locking members 14 and the corresponding bolts together form a board lock means for securing the retainer device 1 onto a printed circuit board (not shown). During assembly, the locking member 14 is positioned from the opening 1311 onto a base of the cavity 131, with the threaded hole thereof aligning with the hole 1312. A substantially L-shaped positioning metal plate 15 defines a hole 151 therein for securing around the vertical portion 141 of the locking member 14 and has a tab 152 extending from one side thereof for engaging with a reception hole 132 defined in an upright wall of the seat 13. A bent portion 153 formed on another side of the positioning metal plate 15 engages with a recess 1313 defined in an outer lower wall portion of the seat 13. After the locking member 14 is fixed in the cavity 13 by means of the positioning metal plate 15, the retainer device 1 may be positioned on a printed circuit board and fixed thereon by the bolts.
During assembly, the alignment of the locking member 14 with the hole 1312 becomes tedious and time consuming. Moreover, the extra positioning metal plate 15 and the laborious assembly thereof with the locking member 14 increases assembly time and manufacturing costs. In addition, the clamping arms 12 occupy too much space and are easily damaged during transportation due to the extended length thereof. Therefore, an improved retainer for overcoming the above problems is requisite in this field.